When Jallen was 9-years-old she was invited to the Camelback Adaptive Ski Camp in Tannersville, Pa., and was instantly hooked on the sport. While instructors initially wanted to put her in a bi-ski tethered to an instructor, Jallen insisted on learning to ski standing up.

Jallen quickly developed as a ski-racer through the Pennsylvania Center Adapted Sports, a chapter of Disabled Sports USA. She was first named to the U.S. Paralympics Alpine National B Team in 2011 at only 15-years-old. She is the second-youngest member of the national team, just two months older than teammate Staci Mannella.

Jallen was born with a rare birth defect called CHILDS, Congenital Hemidysplasia with Ichthyosiform Erythroderma and Limb Defects Syndrome. CHILDS is a chromosomal disorder that affects the entire left side of the body, leaving Jallen with only one leg and one fully developed arm.